Flux oil and method of revivifying asphalt roads therewith



Patented May 26, 1953 UNITED. STATE OFFICE FLUX OIUANDLMETHOD or REVIVIFYING ASPHALT ROADS THEREWITH") Claims (01, 94;.g i

This invention relates tov a method for revivi i f ying' i or reconditioning asphalt roads; -and--pa=r-' ticularly'to a flux oil particularly suitable-for such uses.

Asphalt-roadshave been found to harden grad 5 ually over a periodof years 'dueto-losses of volatile materials from the asphaltanddue to oXidat'ion-ofthe asphalt, or due toother'unex plainedphenomena, which result in cracking, raveli-ng-,= and generaldeterioration of the roadso that 'it becomes unsatisfactory for further-use. At this-sta'g-eof deterioration theasphaltcx tractable by-the Abson method (American Soci-- etyfor Testing Materials (ASTM) Proceedings vol. 33, -1933,Part II,--p. 704) is found to-have a penetration of-about l5-or less at 77 F; by the ASTMmethod (ASTM Standards-part III, pages 220-22l, Method D5 25" using the 100 gm. wt. for* five seconds) 1' It has become-brittle and unsatis-" factory' as a binder. It iscustomaryat'this stage either to 'apply an additional increment of new" road overthe old road, tacking the two together with liquid asphalt' or road oil, or to tear up I a pa'rt oral]. ofthe oldroad; applying 'a refreshing? or revivifying-coatingof'liquid asphalt or road oil, and spread and-compactthe' resulting -ma=' terial. Ineither type of operation theoil" which is normally usedis a liquid asphalt, road'oil'or' fuel oil which is parafiiriic or relatively nonaromatic in nature'p-and'is a residual oilwhich contains its normalcontent such as about'10%to 4.0% of-asphaltenes; which" are-black infusible bodies which are insoluble in light hydrocarbonssuch as propane, butane-or pentane or the like. Such'oils can not 'di'ssolvernuch more asphaltenes 3 than they already contaiiiand are rather poor solvents for asphalt in general, and are particularly poor. solvents for the residual non -volatile--- asphalt: in'the deteriorated road. Consequently i they have littletendency to revivify'theoldas- 40 phalt by softening it, and do nottendto-birid -the" asphalt and aggregate particles" as'tig'htlyz;as-- might be desired, and this results in relativelyrapid deterioration of the" reconditioned roadz- I have d-iscovered a method of reviv-if-yiiig roads? which have deteriorated as above described, which method involves use of a flux oil of suitable viscosity and of highly aromatic nature. Preferably this highly aromatic flux oil should be relatively free from asphaltenes and'should have a viscosityzwithima definite range whichiinsu-res propenipehetration and 'rev ivific'ation -of the olda'sphal t Such nux oils m'ay be readily prepare forsqexample; by blending a heavy 0il -having "aviscos'ltyg reater thanabout 800 0 seconds safybdlt gallovwit to C-soak-ior aday: or more":

mits-rthevfiuir 011 to penetrate the: zaggloinerates; making them easier-"to reduce to 'size byfurther Universal .1 SSU)" at. Fl, suchas .an extract from th'e"solvent'xreflning' .cf a viscous lubricatingw oil-#withfia lighti'oirhavingi a viscosity below about 200 SSU atIOO -F suchiasia' spray oilextractor: the like tdiobtaina fluxoil" having a viscosity withintherange'of.aboutJ300 to 8000 SSU atl-OO" F; a viscosity:'gravity constant greater than. about 0.92, and containin'g-i-not over-.about-rl%' of as phaltenes.

13y" employing 'a fluxnilsuch' as above, andde: scribed more fully-belowythe asphalt in :the-"old."

road :which' has deterioratedp is 'irevivifiedr, the

agglomerated lumps: ofiilthe old road. .are more readily penetr'ated and can subs'equentlya be more readily broken up, and the agglomerates are more" readil yicoated-with the fiux oil so thati-they"area. very tightly bound-together, and the resulting:

road deteriorates much less rapidlyi It is an obj-ectof this inventionsto provide an: improved ihet'hia'd for' re'vivifying deteriorated as purposes?- Other objects -will-appear :inithe fol' lowing description of my invention. y In revivift in'g -a deteriorated asphalt road by the inethdd of this' invention the surface of the road is' -first broken-up by scarifying with a ha-r'-" row or lik'eequipment, digging up'the' entire road if it" is'relatively thin of digging up-about-two'-- inch theread is thicker.- Itisfdesiredthat the resulting-lumpsro'r at least the" agglomeratesybywhich -=to about sir inches .01 the surface where term is meant the particles or lumps containing both aggregate and asphalt, be reduced in size to about one-half inch diameter or less. Rocks of somewhat larger size may be tolerated, but clay balls if present should be broken up and thoroughly mixed into the remainder of mixture. Th'e' reduction in size of the agglomerates to the sp'ee'ified-diameter of about one-half inch or less maywbe accomplished simply by harrowing, or by. olling with a sheepsfoot roller, discing, or the ike operations. Where the road is very seriouslgii deteriorated, it is difiicult to break it up,

and the agglomerates or lumps obtained merely by h'arrowing may be rather large, much larger than fist size for example. In this case it has b'erif' found desirable to spray the flux oil of this invention over the roughly broken up road and This per;-

"ng ,"--sheepstdct rolling Zor otI-ier operation. 1

the flux oil of this invention is sprayed over them, the mixture is preferably allowed to stand for a period of at least an hour and preferably a day or more, but not over about a week, and is then leveled and amalgamated by pressure, such as by rolling with a roller. If sufficient flux oil was applied in the course of reduction of the agglomerates to size, no additional flux oil need be added thereafter. The total amount of flux oil to be used as above may be between about 1% and about 15% of the weight of the agglomerates. When employing the flux oil of this invention such revivified roads will have unusual water resistance and excellent wear characteristics.

In the second of the conventional methods of revivifying asphalt roads described above, the deteriorated road surface is not broken up, but a new increment of surface is applied over the deteriorated road surface, sealing the two together with a tack coat of liquid asphalt. It has been found that such increments of surface in the past have frequently tended to separat from the old surface and thus make such methods of revivifying unsatisfactory. I have found that this general method of revivification is greatly improved if the flux oil of this invention is employed as a tack coat to bind the old surface to the new surface instead of liquid asphalt. The new increment of surface is preferably prepared as described below, employing the flux oil of this invention, but any type of increment of surface may be employed as long as it is an asphalt containing surface. In this operation, the old surface is covered with a coating of the flux oil of this invention, and the new surface is applied thereto. Preferably the old surface is scarified somewhat before or after covering it with the tack oil. Also a coating of the flux oil may be applied to the old road surface before and after scarifying. The new surface is then applied, and the two surfaces are amalgamated through the flux oil by application of pressure, such as by rolling.

The flux oil of this invention, as stated above must be highly aromatic in nature. The aromaticity is defined for convenience by its viscosity-gravity constant (VGC) as described by Hill and Coates in the Journal of Industrial and Engineering Chemistry, vol. 20 (1928) page 641. The viscosity-gravity constant should be greater than about 0.90, and preferably greater than cosity range for the flux oil is between about 300 and 8000 SSU at 100 F.; however, flux oils having lower viscosities such as down to about SSU at 100 F. may be employed in the above revivification processes in some instances, if they are highly aromatic in nature. As stated above the flux oils are conveniently prepared by blending a high viscosity extract with a low viscosity material, although in many instances blending may be unnecessary. The high viscosity material will ordinarily have a viscosity greater than about 300 SSU at 100 F., while the low viscosity material will ordinarily have a viscosity less than about 200 SSU at 100 F. Such blended flux oils are preferred, since they insure the presence of a relatively high proportion of relatively non-volatile material in the flux oil, and thus reduce the rate of volatilization of oil or other deterioration of the revivified asphalt, and yet provide for easy handling and ready penetration. Blends containing a major proportion of the more viscous component are preferred. Blends containing about 5% to about 40% of the lighter component are generally suitable. The asphaltene content of the flux oil should also be low, since the deteriorated asphalt generally contains an overabundance of asphaltenes. When the lubricating oil extracts prepared by solvent extraction of lubricating oil distillates are employed, the asphaltene content of such extracts is suitably low. The viscosity indices of th flux oils of this invention are extremely low, in agreement with their aromatic nature. Usually they are well below zero. The flash point of the flux oil as measured by the Cleveland Cup Method is preferably greater than 300 F. Lubricating oil extracts will generally have flash points above 400 or even above 500 F., whereas the flash points of the lighter extracts may be about 300 F. or lower. The API gravities of the flux oils of this invention generally will be very low, such as below about 15, and frequently below 10, i. e., the oils may be heavier than water in many instances. The olefin content of the flux oils should be relatively low, since it is well known that oils containing large proportions of olefins, such as cracked distillates, fuel oils, gas oils, etc., are not desirably stable to oxidation. Thus the presence of cracked materials in the flux oils tends to increase the rate of deterioration.

As specific examples of flux oils of this invention the following materials are described:

Viscosity, G sso, a V00 1 Flash 0 API F.

Heavy Oils:

SAE 30-40 Lubricating Oil Extract (1H) 3 60, 000 10. 4 0. 939 510 SAE 20-80 Lubricating Oil Extract (2H) 8,000 11.0 0. 941 450 Lubricating Oil Extract (3H) 3 100, 000 5. 3 0. 973 475 Light Oils:

Spray Oil Extract (1L) 110 14. 5 0. 945 310 Transformer Oil Extract (2L) 70 16.0 0. 939 280 Kerosene Extract (3L) 31 26.0 3 0. 93 142 Blended Flux Oils:

20% IL and IE above 8, 000 ll. 2 0. 938 450 10% 3L and IE above 5, 000 12. 0 0. 934 480 30% 2L and 70% 2H above 1, 000 12. 5 0. 943 370 30% 2L and 70% 311 above 3, 000 9.1 0. 970 360 1 Viscosity-gravity constant. 3 Cleveland Open Cup. 3 Extrapolated.

about 0.92. As an example of the significance 70 Although only a few specific blends are shown of the VGC test, a typical aromatic Western lubricating oil extract will have a VGC of about 0.93 or higher, whereas a well refined parafiinic Eastern lubricating oil may have a VGC of about 0.81 or less.

above, similar flux oils having the characteristics described previously may be employed in the processes of this invention. The heavy extracts described above are prepared by solvent extrac- As stated above the preferred vis- 75 tion of lubricating oil distillates from paraffinic aesaeea;

Similar-a- 5 rs.

(reissuedzaswRe Nos17 ,985)owhiclninvolvescoats ingsaa stoneagerre ataawith aJfilIXa' saddingai powderediasphalt, mixing anddayingtheimixture and vamalgamating gbynapplication; ofisipressure The flux oilirhere 'was'sza rfuelcfloilt: o emi-liqui asphalt. iA later-7U..S.-:Patenth2;22.0;67fl describe u an improvement in this process, in which the fiu xrz oil isea heavylubricating=: oil?extract. I have now found that the flux oil of the present invention is a :markeda; improvement .overeanyssof rtheioils described incthe prion aIIts SlII-CQ it :has: the advantage not only of high aromatic content, but of propei fluidity and penetration ability. Thus;' for building-"new roads-accordihg to thisinven tion an aggregate and-a powdered-asphalthaving a melting' point -aboveabout 1'75""F. are mixed with'the flu'x' oilof this'in'vention so that" the particles become coa-tedtherebm and the -resulting substantially homogeneous composite 'mix ture is applied to the-road bed andamalgamated by the application of -pressurer The preferredflux oil of the present invention-is particularlysuitable forthi-sprocess-because its'oreadily coats the aggregate and the -asphalt='-'parti-cles, vandal lows sufiicient penetration of theasphalt Smth'at" amalgamation takes-place morereadily and more completely,- and the" stabilitymf the road is "in-=- creased.

Although the-asphalt=,- aggregate -and "flux oil may be mixed simultaneously! orrthe asphalt and flux oil may be mixed first, in the preferred mode. of operation, the aggregate'isfirst. mixedl'with" the fiux oil";-'allowing-th'e"flux"'oilto" coat" and/or penetrate the aggregate, and thereafter the solid asphalt is mixed in, usin a concrete mixer or any similar mixing apparatus in these operations. The asphalt generally becomes coated with flux oil and adheres to the coated aggregate particles to form a further coating without as yet amalgamating therewith. The coated particles move freely with respect to each other and are readily spread uniformly over the roadbed. The asphalt amalgamates with the flux oil when cold only under applied pressure to form a substantially homogeneous composite binder, which in turn serves to amalgamate the coated aggregate. Thus the coated aggregate and asphalt particles are amalgamated in position by application of pressure as by rolling. It appears that flux oil is absorbed into the pores of the aggregate, and is gradually liberated therefrom to the asphalt, thus acting as a continuous revivifier as the road ages. This may be one reason for the exceptionally long life of such roads, especially when the preferred flux oils of this invention are employed.

As described above the preferred flux oils used in this new road construction are those having viscosities between about 300 and 8000 SSU at IOQZZJFEEandtVGCSsi greater: thamabout:0192;;and are1= composed;:o-f a blend containing L-amaj or pro-- portion f'ofisheav .s:aromaticsmaterial;havingzvisa-- cosityk-above "BOOFcand: preferablysyabove about and a minor- :proportion': of .a l light oil l havingsa viscosityzslowersthanaabcut szooaSSHnat 1100 FL Preferably thiszfiux :oilshouldoberrelatively free from: asphalteneszi-and olefinsfor:cracked hydro? r 3carbonsxas'::described:i:.'ab.ove; rand..ishould: have a Theiaggregateatof be used inxmakinginew roads.- may:bexstoneiorrsanctitor evenzsoiLas;employedd'inz; conuenti'onalc'road construction:practice. The"); :3. iasphalteushould ice .1 .a izrelativelyibrittlel.material. r

hayingi'jhigh-cmeltingzt pointgc'above :about 175?" 2 Itscpenetration should. e'rz-lesszvthani aboutLZO: 8.17:5. 77ZF;.' Anasphaltwhich:isiprepared by: preoipietati'onidrom anzasphaltic oil;.'usin'g aprecipitanta. oapsucha'as propanenorzthe; likei isip arti-cularly :suit i ablei'tz Such; asphalt's :andxtheir' 'preparationxsarezzr thoroughly described in the above U. S.. Patent;.;

2,220,610; Other:suitabletiasphalts.may be: made by :steamzblowingzorxbyrair blowingpx Air blowing; 50f highly: aromaticvheavy: oils.,such*as'. the heavy I lubricating 4.011 lextractstdescribed: rabove or .exe:

tract fractions; from solvent extraction :of reside.

aboutzl and about loiperrcentnby weightzofthe ag iegateppreferably:zbetween about 2 and 5%,. andithe fiuxoil be between about 11' and':l.5'%',

z ref-erably b'etween-zaboutfl and: 6% 0f stheiaggre gate."v It is desirable:-.that the asphaltiinthelfin ishedvroad have 'a' penetrationuatzfl'ihF. of about i 30.:toi3ilfiw As an zexample 10f. apsuitable mixture; an aggregate icomprisingnlro'ck::andmsand is mixed and ,,20% of athersprayzoilzextract"(1L) described inthe tableabovegand" "2130111313 %.of a powdered-I asphalt having a melting: .pointrof'about: 250F111; Whe11r -spr ead;evenly. 0111a roadbe'd and amalgame ated by rollinggqan.:excellent roadris made-1:.

Modificationstofi this invention :whichwould occur-to. one skilled in zthezart :arer-to JbeiincIud'ed in 1 thea-vz-scope ofzrthe invention :iasxdefin'ediuin tthe 1 I claim:

1. A method for revivifying deteriorated asphalt roads which comprises breaking up the surface of the deteriorated road to form lumps; applying to said lumps without removal from the road bed a coating of a highly aromatic petroleum extract oil having a viscosity between about '70 and about 8000 SSU at 100 F., a viscosity-gravity constant greater than about 0.90, and a flash point above about 300 F., and consisting essentially of aromatic-type hydrocarbons substantially free from asphaltenes, olefines, and cracked hydrocarbons, said extract having been prepared by a process involving contacting a straight run fraction from an aromatic hydrocarbon-containing crude petroleum with a liquid solvent selective in its action toward aromatic hydrocarbons so as to physically dissolve therein the desired aromatic hydrocarbons without dissolving the undesired non-aromatic hydrocarbons; allowing the coated lumps to stand for at least one hour; and thereafter amalgamating the coated lumps by the application of pressure. 2. A method for revivifying deteriorated asphalt roads which comprises breaking up the surface of the deteriorated road to form agglomerates having a maximum diameter of about onehalf inch; applyin to said lumps without removal from the road bed a coating of a highly aromatic petroleum extract oil having a viscosity between about 300 and about 8000 SSU at 100 F., a viscosity-gravity constant greater than about 0.92, a flash point above about 300 F., and consisting essentially of aromatic-type hydrocarbons substantially free from asphaltenes, olefines, and cracked hydrocarbons, said extract having been prepared by a process involving contacting a straight run fraction from an aromatic hydrocarbon-containing crude petroleum with a liquid solvent selective in its action toward aromatic hydrocarbons so as to physically dissolve therein the desired aromatic hydrocarbons without dissolving the undesired non-aromatic hydrocarbons; allowing the coated lumps to stand for at least one hour; and thereafter amalgamating the coated lumps by the application of pressure.

3. The method of claim 2, wherein the highly aromatic petroleum oil comprises between about 60 and about 95 per cent by weight of a petroleum lubricating oil extract having a viscosity above about 8000 SSU at 100 F. and a viscositygravity constant greater than about 0.92, and between about and about 40 per cent by weight of a light petroleum oil extract having a viscosity below about 200 SSU at 100 F.

4. A method for revivifying deteriorated asphalt roads which comprises applying to the surface of the deteriorated road a coating of a highly aromatic petroleum extract oil having a viscosity between about 70 and about 8000 SSU at 100 a viscosity-gravity constant greater than about 0.90, and a flash point above about 300 F., and consisting essentially of aromatictype hydrocarbons substantially free from asphaltenes, olefines and cracked hydrocarbons, said extract having been prepared by a process involving contacting a straight run fraction from an aromatic hydrocarbon-containing crude petroleum with a liquid solvent selective in its action toward aromatic hydrocarbons so as to physically dissolve therein the desired aromatic hydrocarbons without dissolving the undesired non-aromatic hydrocarbons; applying to the coated road an increment of new asphalt paving;

and amalgamating said increment with the old road by the application of pressure.

5. A flux oil for asphalt roads comprising between about and about percent by weight of a petroleum lubricating oil extract having a viscosity above about 8000 SSU at F. and a viscosity-gravity constant greater than about 0.92, and between about 5 and about 40 per cent by weight of a light petroleum oil extract having a viscosity below about 200 SSU at 100 F., said flux oil having a viscosity between about 300 and about 8000 SSU at 100 F., a viscosity-gravity constant greater than about 0.90 a flash point above about 300 F., both of said extracts consisting essentially of aromatic-type hydrocarbons substantially free from asphaltenes, olefines, and cracked hydrocarbons, and both of said extracts having been prepared by a process involving contacting a straight run fraction from an aromatic hydrocarbon-containing crude petroleum with a liquid solvent so as to physically dissolve therein the desired aromatic hydrocarbons without dissolving the undesired non-aromatic hydrocarbons.

FREDERICK S. SCOTT.

References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS Country Date France Nov. 8, 1934 Number Re. 17,985 635,430 761,939 801,938 1,077,081 1,729,573 2,002,652 2,039,026 2,069,929 2,183,783 2,220,670 2,310,194 2,340,779 2,349,445 2,360,446 2,363,244

Number 

1. A METHOD FOR REVIVIFING DETERIORATED ASPHALT ROADS WHICH COMPRISES BREAKING UP THE SURFACE OF THE DETERIORATED ROAD TO FORM LUMPS; APPLYING TO SAID LUMPS WITHOUT REMOVAL FROM THE ROAD BED A COATING OF A HIGHLY AROMATIC PETROLEUM EXTRACT OIL HAVING A VISCOSITY BETWEEN ABOUT 70 AND ABOUT 8000 SSU AT 100* F., AND VISCOSITY-GRAVITY CONSTANT GREATER THAN ABOUT 0.90, AND A FLASH POINT ABOVE ABOUT 300* F., AND CONSISTING ESSENTIALLY OF AROMATIC-TYPE HYDROCARBONS SUBSTANTIALLY FREE FROM ASPHATENES, OLEFINES, AND CRACKED HYDROCARBONS, SAID EXTRACT HAVING BEEN PREPARED BY A PROCESS INVOLVING CONTACTING A STRAIGHT RUN FRACTION FROM AN AROMATIC HYDROCARBON-CONTAINING CRUDE PETROLEUM WITH A LIQUID SOLVENT SELECTIVE IN ITS ACTION TOWARD AROMATIC HYDROCARBONS SO AS TO PHYSICALLY DISSOLVE THEREIN THE DESIRED AROMATIC HYDROCARBONS WITHOUT DISSOLVING THE UNDESIRED NON-AROMATIC HYDROCARBONS; ALLOWING THE COATED LUMPS TO STAND FOR AT LEAST ONE HOUR; AND THEREAFTER AMALGAMATING THE COATED LUMPS BY THE APPLICATION OF PRESSURE. 